Extrude object along curve not working
Well I'm not sure what technique you are using to "extrude along a curve".  The array modifier is one way to do it as moonboots mentions.  Another one, which I used to create the image below, is to convert your profile mesh to a curve, then use it as the "Bevel Object" of your arch form curve.  You can then convert the resulting curve to a mesh (as I've done with a duplicate in the screenshot).  You will need to be sure to apply location, rotation, and scale to your objects, INCLUDING the arch curve object, to get this to work right, and even after that you may need to rotate the profile (and apply the rotation) so that the right bits are pointing in the right direction.